When fabricating a semiconductor laser having an incorporated modulator, it is necessary for two semiconductor structures including two light guiding layers of different compositions to be coupled together end to end. This forms two successive segments belonging to the same optical waveguide and respectively performing the two functions of creating and of modulating light.
Until now, such coupling has been performed by making a first semiconductor structure in both segments and then eliminating it by etching that is limited to one of the segments. The second semiconductor structure is then made adjacent to the first by epitaxial deposits.
In known methods, use is made either of wet etching by means of a liquid reagent, or else of dry etching by means of a reactive plasma or of a beam of reactive ions.
The performance of components fabricated by those known methods is not very reproducible.